<nav id="nav-single" class="nav-single">
    <h3 class="assistive-text">Post navigation</h3>
    <span class="nav-previous">
        {% if prev_post %}
            上一篇 <a href="/blog/pages{{ page.previous_page_number }}/?p={{prev_post.id}}"> {{prev_post.post_title}}</a>
        {% endif %}
    </span>
        
    <span class="nav-next">    
            {% if next_post %}
                下一篇 <a href="/blog/pages{{ page.next_page_number }}/?p={{next_post.id}}"> {{next_post.post_title}}</a>
            {% endif %}
    </span>
</nav>